1. Field of Invention
The present invention relates to an antenna and, in particular, to a dipole antenna.
2. Related Art
Antenna is an important element for transmitting and receiving wireless signals in a wireless product; without it, the wireless product would not be able to work properly. Therefore, an antenna plays an essential role in wireless communication.
The rapid development of wireless communication brings various products and technologies of multi-frequency communication, and the new products provide with the functions of wireless communication to satisfy consumers' needs. Current demands for the products are not only the basic functions but also the additional functions such as global positioning system (GPS) service, Bluetooth communication, and Mobile Internet; this makes the process of choosing the antenna become more complex. Since these additional functions need to be carried out with hardware elements, the increasing number of such elements would take more space in the products with small sizes. Hence the space for the antenna would keep decreasing and at the same time, the antenna still needs to be properly integrated with other elements in the product.
Although there are various types of antennas, a dipole antenna is the most commonly used in wireless communication. FIG. 1 is a schematic view of a conventional dipole antenna. With reference to FIG. 1, a rectangular first conductive part 121 and a rectangular second conductive part 122 of the conventional dipole antenna 1 are disposed on a surface of a substrate 11. A conductive element 15 connects a feeding point 13 and a ground point 14 to feed the signal so as to generate the frequency resonance, such that the antenna could operate. However, because the conductive parts are disposed on only one surface of the substrate of the conventional dipole antenna, the size of the substrate will be increased if more conductive parts are added.
As mentioned above, it is difficult to reduce the size of the conventional dipole antenna. Therefore, the subject of the present invention is to design a dipole antenna with a reduced substrate size and the same functions.